BuzzFeed is closing its news division as part of an effort to cut 15 percent of its work force after years of mounting financial difficulties, BuzzFeed CEO Jonah Peretti told staff Thursday morning, marking the end of a click-chasing, social-media-driven content factory that spawned many imitators in the 13 years since it launched.

Peretti sent a memo to staff Thursday morning, obtained by CNN’s Oliver Darcy, informing them that Buzzfeed News would be shutting down because it is no longer financially viable. Some of the BuzzFeed News staff will transition to the news vertical’s parent platform, Buzzfeed.com, which will continue on.

Founded in 2011, BuzzFeed News became a traffic giant during the social-media era but has struggled to adjust to new industry dynamics.